org.apache.openjpa.jdbc.sql
Interface Union

All Superinterfaces:

SelectExecutor

All Known Implementing Classes:

LogicalUnion

public interface Union
extends SelectExecutor

SQL UNION.

Author:

Abe White

Nested Class Summary

static interface

Union.Selector A callback used to create the selects in a SQL union.

Method Summary

void	abortUnion() Force the use of a series of standard selects rather than a true UNION.
String	getOrdering() Get the union-level ordering, if any.
Select[]	getSelects() Return the selects that make up this union.
boolean	isSingleResult() Whether this union will return at most a single result.
boolean	isUnion() Whether this is a true UNION, rather than a logical combination of independent selects.
void	select(Union.Selector selector) Select data using the given selector.
void	setSingleResult(boolean single) Whether this union will return at most a single result.

Methods inherited from interface org.apache.openjpa.jdbc.sql.SelectExecutor

execute, execute, getAutoDistinct, getConfiguration, getCount, getJoinSyntax, isDistinct, isLRS, setAutoDistinct, setDistinct, setJoinSyntax, setLRS, supportsLocking, supportsRandomAccess, toSelect, toSelectCount

Method Detail

getSelects

Select[] getSelects()

Return the selects that make up this union.

getOrdering

String getOrdering()

Get the union-level ordering, if any.

isSingleResult

boolean isSingleResult()

Whether this union will return at most a single result. Setting this flag makes it more efficient to execute logical unions that are actually made up from multiple selects executed in batch.

setSingleResult

void setSingleResult(boolean single)

Whether this union will return at most a single result. Setting this flag makes it more efficient to execute logical unions that are actually made up from multiple selects executed in batch.

isUnion

boolean isUnion()

Whether this is a true UNION, rather than a logical combination of independent selects.

abortUnion

void abortUnion()

Force the use of a series of standard selects rather than a true UNION.

select

void select(Union.Selector selector)

Select data using the given selector.